Page 3 stunnas!

To begin our week of guest editors for the Guardian's arts coverage, Glasgow band Franz Ferdinand publish a different take on tabloid newspapers' topless pictures - and ask the photographer who took
the image, Wolfgang Tillmans, to explain how and why he made it

In the 1970s in Germany there was a hardcore socialist magazine called Konkret that, for a time, used pictures of naked women on its front covers. Nothing inside the magazine reflected this: the stories inside were all about working towards changing society. The editors were just taking advantage of the fact that sex sells to spread that message.

It's fascinating when sex is used to sell something that otherwise has intellectual high standards. Why, however, are the naked people shown in newspapers and magazines never men? This is blatant inequality. If people are equal, why would the sight of a naked man be undesirable - or, worse, obscene?

When I was asked to provide a page-three image for G2, I obviously wanted to do something that challenged the standard formula. Conventional page-three pictures aren't subversive. They're not even inclusive: they serve only half the population. My page three would be as modern as possible.

I chose an unpublished photograph which I had taken recently. It shows a woman sitting in a relaxed fashion, with her legs spread, as though she is at breakfast. She is nude and the image shows her body from her belly button to her knees. The facts of her body are just there - natural, striking in their presence, and fascinating for it.

The photograph shows very clearly what a woman's genitals look like - something few men, even heterosexual men, have any real idea of. Its focus is sex, but it also acknowledges that this is where we come from. The image doesn't beat around the bush: it isn't titillating, nor is it shocking. However, it was felt to be too explicit to be published in G2.

I first started thinking about playing with the idea of male and female nudity in the early 1990s. The fact is, toplessness in a man is not equal to toplessness in a woman. For a man to experience the same level of exposure and commitment to the image as a woman posing topless, he must appear bottomless.

That was the principle behind my series Like Brother, Like Sister, created for iD magazine in 1992 and showing a man and a woman side by side, she topless, he bottomless. The title had nothing to do with the relationship between the people in the photographs (both friends of mine); it simply registered the equality between the man and the woman. To the managers of WHSmiths, however, the title referred to incest and the images were obscene. The chain refused to stock that issue of iD, almost closing the magazine.

Two years later, I photographed another set of nudes for a Japanese magazine. My G2 page three - John and Paula, Sitting Bottomless - comes from that series. The magazine published John and Paula, Sitting Bottomless, but couldn't do so without it being censored. And so John appeared with a big orange dot covering his penis.

It's important to show acts of censorship in this way - because otherwise no one notices that it is actually happening. This is what was great about Todd Solondz's movie Storytelling. It has a sex scene that is so explicit the producers wanted it cut. But Solondz refused. Instead he put big red bars over the actors' genitals for the duration of the scene. Every time the actors move, the bars move too. It looks hilarious - but it's much better than if the scene had been cut altogether.

Censorship varies so much geographically. On the continent most publications will depict a naked man or woman. America, though, is completely different. Since the Mapplethorpe scandal in 1989 (his male nude photographs caused such a furore that rightwing politicians voted to ban government funding for "obscene or indecent" art), galleries can't afford to take any risks. In 1996, I made an installation for a group show at the Museum of Modern Art in New York. All the work had to be screened by the curator. He waved through every female nude - but every male nude became the subject of discussion, and several were vetoed.

It's ridiculous that supposedly rational people can be so blind to this inequality. And it's not just an inequality between men and women. It is still considered more obscene to show two men kissing before the watershed on TV than it is to show two men kill each other. How can something as atrocious as the destruction of two men be acceptable, and the sight of men kissing scandalous? This isn't just upsetting. It's obscene.

Essentially, ideas of obscenity are defined by powerful political interests. Sexuality is one of the few things that is absolutely free - sex can sell, but sex between two people isn't marketable. It's the one thing that people can do for fun for free. A lot of people have a problem with this - they think sexuality needs to be controlled.

When people deem an image obscene, often it's not just because it shows someone naked, but because it shows someone who is empowered. Since the mid-90s youth magazines, such as the Face, have prided themselves on pushing the boundaries with their fashion stories. There was a lot of very crass sexual photography used at that time. But the models were always tools of a male fantasy - they were never empowered beings. Such images may have shouted, "Hey, I'm shocking", but their risque wildness was just self-congratulatory. This style of fashion photography shared all the faults of an ordinary tabloid page three.

If sex and violence are used to entertain people or to market something, they are acceptable. It's aimless, directionless sex that shocks and scares people most. Normally when women are photographed they are offering themselves in some way. People don't mind that - it's when self-affirmed, powerful women are shown to be in control of their sexuality that people feel threatened. And yet to me such images are harmless - innocent, even. How odd, that the most innocent image should seem the most obscene.

Nudity is such a powerful thing that I try to avoid using it gratuitously in my photography. And when I do use it, I want to do so only in a disarming - and so shocking - way. I want to show human beings who are at once vulnerable and confident about who they are, about themselves inside their bodies. This is such a fragile thing to represent that I don't want to overdo it - which is why I have taken perhaps just three dozen images involving nudity. Although I'm still interested in nude equality, I haven't returned to the image of John and Paula I took in 1994. The pictures I took then still make their point, one there is no reason to carry on making.

Ten years ago, I couldn't have created such a matter-of-fact image of a woman's body as I did in the crotch shot. That was a step forward for me. And the friend who modelled for it is extremely happy with the picture. She is happy because it shows the vagina as something that is actually present: not as a negative, a hole, as it is in many men's imaginations, but as an organ with protuberances. And there is nothing obscene about that.

·Franz Ferdinand say"When we were asked to edit G2, we were thrilled, but a bit surprised at the foolhardiness of a broadsheet allowing a daft pop group to take the reins. It reminded us of the Oz magazine trial and this discussion led us on to our first theme. The idea of an image on page three of G2 which would challenge readers' concepts of obscenity appealed to us."